Monitor soybean aphid populations on PIPE

by Carol Pilcher, Department of Entomology

The Pest Information Platform for Extension and Education (PIPE) was developed in 2004 to provide electronic access to data for soybean rust. In 2006, soybean aphid was added to the system, and it is anticipated that other pests will continue to be added to this national monitoring network. You can view the current soybean aphid monitoring results at www.sbrusa.net (to view the aphid map, select the second dropdown box under the date on the left-hand side of the screen).

Currently, extension field agronomists are monitoring fields throughout the state of Iowa for soybean aphids. In each location, they examine 20 plants and determine the presence or absence of aphids. If aphids are present, they count the number of aphids per plant. This information is then recorded and entered in the national database on a weekly basis. PIPE provides growers with a tool to tell them when to start scouting for soybean aphid. It also gives them a general idea of the potential populations in their county. It does not, however, indicate the number of aphids in their field. Aphids are a sporadic pest and fields that are only separated by a road can have dramatically different populations. It is essential that a grower scout each field on an individual basis for this particular pest.

To date, aphid numbers have been relatively low (see "Soybean aphid numbers increase . . . and decrease"). Extension field agronomists report that they are finding aphids, but again, the numbers are low. What will happen to aphid populations? That depends on two conditions: weather and the natural enemies of the aphids. Warm and dry weather conditions favor aphid development and reproduction. The recent weather conditions have been ideal for aphids.

Continue to keep track of aphid populations through the ICM newsletter and the PIPE Web site, and keep track of what is occurring in your individual fields.

Carol Pilcher is the interim director of Iowa State University's Pest Management and the Environment Program and coordinator of the Integrated Pest Management Program.

This article originally appeared on page 206 of the IC-498(17) -- July 2, 2007 issue.